Author Topic: A 507,000 Mile Harley Davidson Motorcycle Using Automotive Motor Oil Only?  (Read 843 times)


  • Hero Member
  • *****
  • Posts: 968
If you read literature on motorcycle oils from motorcycle and motor oil manufacturers, they all recommend using only motor oil specifically formulated for motorcycles. Mobil Oil list several reasons for this on their website, and here is a copy of their explanation:

It's a little hard to generalize about the difference between Mobil 1 passenger‐car motor oils and Mobil 1 motorcycle oils. That's because not all viscosities of Mobil 1 passenger‐car oils have the same levels of zinc and phosphorus, and there are even greater differences between the two Mobil 1 motorcycle oils.
  • In general, Mobil 1 motorcycle oils have additive packages formulated for use in both motorcycle engine and transmission operation.
  • For passenger vehicles, fuel economy and emission system protection are higher priorities. These require low phosphorus systems and the use of friction modifiers.
  • Motorcycle oils do not require friction modifiers for fuel economy and for better clutch friction less/no friction modifier is optimum.
  • Motorcycle oils allow the use of higher levels of anti‐wear additives such as ZDDP (phosphorous).
Plus there are the overall benefits of Mobil 1 synthetic oil compared to those of conventional motor oils, whether they be for passenger cars or motorcycles:
  • Superior long‐term engine protection
  • Superior high‐temperature stability
  • Excellent low‐temperature starting
  • Outstanding engine performance
  • Low volatility/low oil consumption

Motor oil used in gas powered cars and trucks is designed only for use in the automotive internal combustion engine. Unlike cars and trucks, many motorcycles share engine oil with the transmission and clutch. The Harley Davidson big twin engine is one exception. Harley Davidson does separate engine oil from the clutch and transmission on many models. However, unlike cars and trucks, the Harley big twin engine is mostly air cooled and produces more heat than a car engine. The most used argument for not using automotive motor oil for your motorcycle is it contains friction modifiers that can cause a motorcycle wet clutch to slip under certain conditions, but what are those conditions? Even after knowing the differences found in motor oils, many motorcycle owners choose to use automotive motor oil because its so much cheaper and easier to get.

One individual named Scotty Kerekes aka Scooter Tramp Scotty, has over 1 million miles of experience using automotive motor oil for Harley Davidson motorcycles. In the video below, his Harley Davidson motorcycle is equipped with an Evolution engine and has 507,000 miles. I doubt all those miles are on one engine, but still that's impressive. Scotty not only use's automotive motor oil for the engine, but also for the primary case where the wet clutch is located. Who can argue that the oil he uses is damaging the engine when he has 507,000 miles on the motorcycle? He said in a video he doesn't ride his motorcycle hard, and prefers slower moving back roads to the interstate, so maybe that plays a part in the longevity of his high mileage motorcycle. Is does make you wonder if the selling points used by oil and motorcycle manufactures is a little exaggerated.

If you do the numbers, Scotty pays about $49.56 for 3 quarts (5qt container) of Mobil 1 15W-50 full synthetic motor oil, 1 quart of Mobil 1 15W-90 full synthetic gear oil for the transmission, 1 quart Valvoline 20W-50 conventional oil for the primary case, and an aftermarket oil filter. It cost $84.95 to buy 5 quarts of Harley Davidson Syn 3 20W-50 full synthetic oil (for engine, transmission & primary), 1 Blk Harley Davidson oil filter and an o-ring for the drain plug. Add $3 if you choose a HD chrome oil filter. Scotty saves $35.39 per oil change by using full synthetic aftermarket automotive motor/transmission oil and filters compared to Harley Davidson syn 3 oil and parts. He says he does an oil change every 7000 to 8000 miles, so during his 507,000 miles on the road he saved $2,242.00 - $2,563.00 on oil changes. All motorcycle blended motor oils come with a premium price. It doesn't matter if it's sold by a motorcycle manufacturer or aftermarket and sold on department store shelves; its all more expensive than automotive motor oil.

Even with Scotty's success using car motor oil in his Harley, I don't think I would recommend it for the reasons listed above. Scotty likes to ride his motorcycle real slow, and you could say he babies it. Most motorcycles are high revving, some produce high heat, and many share engine oil with the clutch and transmission. I think the additives added to motorcycle oil make it a better oil for motorcycles, but is it worth the additional cost in the long run? I don't know......

I should mention Harley Davidson does sell a new full synthetic transmission oil called Heavy Synthetic Gear Oil that is more competitively priced with Mobil 1 full synthetic gear oil. Harley also sells a conventional transmission and primary case oil called Formula + Transmission and Primary Chaincase Lubricant. It's about half the price of full synthetic.

<a href="" target="_blank" class="new_win"></a>
« Last Edit: March 12, 2020, 06:50:57 PM by adminjoe »
John 3:16 For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.